The manufacture of brushes with stiff bristles, brushes with flexible bristles, toothbrushes, and the like is performed in a wide variety of ways. Thus, for example, to manufacture paint brushes or cleaning brushes, the tufts of bristles or hairs are retained by phenol or epoxy resin materials in a receiving box or a handle.
In the case of smaller brushes, such as toothbrushes or precision cleaning brushes, as a rule monofilaments are held in a receptacle either by means of hot-melt materials or by so-called anchors. It is also known to introduce individual monofilaments or tufts thereof into receptacles in the shape of holes, and to weld shut the hole opening.
The known methods are either partially objectionable from the physiological standpoint or are expensive, or they do not allow very small brushes to be manufactured. Thus it has been found especially in the manufacture of very small brushes for electrical cleaning devices, or of very fine cleaning brushes, for example for precision mechanics, that with very small wall thicknesses for the brush bodies, the known fastening methods are not suitable for retaining brush hairs, bristles, or monofilaments, etc. In addition, it is not possible with the known methods to shape the brush or to form the brush surface.
Three U.S. Pat. Nos., 2,653,056, 2,664,316, and 2,397,471 describe the manufacture of brushes with stiff bristles, particularly toothbrushes, with the bristle tufts being fastened in the handle by metal inserts and inductive heating.
EP-0,519,677 describes the manufacture of brushes with stiff bristles using ultrasonic welding.
WO90/00359 describes a method of manufacturing small brushes with stiff bristles, with bristle structures disposed in practically any desired manner. It proposes that either a through opening be provided on a holder, and the bristle tuft be inserted into this opening, in order to pot it, glue it, or weld it from the other side of the holder, or alternatively a blind hole be made in the holder in order to use the remaining covering wall of the blind hole as a welding material after insertion of the tuft.
Finally, EP-A-0,329,939 describes a method and a device for making devices for applying fluid media by means of bristles.
The methods described in the prior art relate firstly to the manufacture of brushes with stiff bristles, with no adhesives or hot melt materials having to be used to secure the bristles or monofilaments that form the bristles, or relate to methods and devices for producing bristle structures or bristle tufts, either by applied heat or by adhesives.
None of the publications known from the prior art is suitable for the manufacture of very delicate and/or very small brushes with stiff bristles or flexible bristles, in whose manufacture the shaping of the tufts is important, or in which special bristle structures are to be produced.